A waffle cut potato chip characteristically has longitudinal ridges and grooves formed in both cut surfaces to give it a corrugated shape. The grooves on one surface are perpendicular to the ridges and grooves on the opposite surface. The grooves are sufficiently deep such that the grooves of one cut surface intersect those of the other cut surface to form a grid of openings in the chip.
The only known commercially available potato slicing machine for making waffle cut potato chips is substantially like that shown in Urschel, U.S. Pat. Nos. 3,139,127 and 3,139,130, manufactured by Urschel Laboratories, Inc., Valparaiso, Ind. as model "CCL". In operation, whole potatoes are received by a central rotating carriage or impeller hub and fed outwardly by centrifugal force into one of several radial guides or impeller tubes which simultaneously rotate and direct the potatoes to a stationary cutting assembly surrounding the impeller hub. The cutting assembly includes a plurality of circumferentially spaced corrugated knives that project into the path of the orbiting potatoes to cut away thin slices of the potatoes, shunting the slices tangentially away from the cutting assembly as they are cut. Means are provided to cause the impeller tubes, and hence the potatoes carried therein, to rotate 90 degrees within the impeller hub in between successive cuts of the potato. In this way the corrugated knives slice the potatoes into thin potato slices having ridges and grooves on one side that are perpendicular to the ridges and grooves on the other side.
Various modifications and improvements have been made to this basic machine. For example, Julian et al. U.S. Pat. No. 4,523,503 improved the knives and the knife holders used to slice the potatoes. The machine, although adequate for its intended function, still has some problems capable of improvement. One of the major problems is bearing life.
The impeller tubes rotate about the impeller hub in order to cause the potatoes to rotate 90 degrees between each successive slice. A bearing is located between the impeller hub and the impeller tube to ensure smooth rotation. This bearing is susceptible to being contaminated by water and solid materials which flow between the impeller tube and the impeller hub. The bearings are about six inches in diameter are very expensive to replace. The contamination of these bearings causes them to have a life of approximately 250 hours. The bearings currently are lubricated by a human consumable vegetable type grease. Even with proper maintenance and greasing schedules, the grease is insufficient to keep the moisture and contaminants from destroying the bearings.
It is therefore an object of this invention to improve the sealing between the impeller hub and the impeller tube to prevent the bearings from being contaminated by water and solid material.
It is also an object of this invention to sufficiently seal the bearings such that a lubricating grade grease may be used to lubricate the bearings.
It is a further object of this invention to provide a relief in the impeller tube to allow moisture to be slung out away from the bearings during operation.
Still another object of this invention is to improve the performance and reduce the maintenance costs of waffle cut slicing apparatus having a central hub which rotates about a vertical axis and at least one rotatably connected impeller tube which rotates about a horizontal axis aligned radially with respect to the hub's vertical axis.